"While Charlie and I search for elephants, our many subsidiaries are regularly making bolt-on acquisitions," he said. "Last year, we contracted for 25 of these, scheduled to cost $3.1 billion in aggregate. These transactions ranged from $1.9 million to $1.1 billion in size."

There are obviously big opportunities to buy companies around the world. Many look to emerging markets like China where growth is hot.

But Buffett has his eyes domestic.

"Our subsidiaries spent a record $11 billion on plant and equipment during 2013, roughly twice our depreciation charge," he said. "About 89% of that money was spent in the United States. Though we invest abroad as well, the mother lode of opportunity resides in America."